Reading nautical charts is nontrivial. They tend to be extremely dense (in areas where you need to use one at all); you have to know a bunch of buoy symbols, implicit rules, and so forth. Switching entirely to an electronic system where you could choose optional display layers and tap unrecognized symbols for help could make navigators’ licensing considerably easier.
Edit: A chart I happen to know a little: http://www.charts.noaa.gov/OnLineViewer/18432.shtml . Notice the cable zones (where you can’t anchor), the international boundary, the shipping lanes (where you’re liable to be run over if you’re not a 1000-ton vessel), the magnetic declination rosettes, the angles showing lighthouse visibility, the warning of local magnetic disturbance, the nature preserves … and not far off this particular chart, there are even markings for unexploded ordnance, left over from exercises in the Cold War. And this is a simpler chart than one you would theoretically use to move an oil tanker through the shipping lane, if you did it on paper. So you can imagine how much a good electronic system could clear things up.